Category Archives: Garden Advice

How to Grow Onions

Onions are often touted as one of the easiest crops for beginners, but many folks need help for good production. Bulb onions can be a bit finicky, and if you don’t provide the correct conditions, your onions won’t bulb up properly. This quick-growing guide will get you on track for a big onion harvest, even if you’re a complete beginner.

Step One: Choose the Right Onions for Your Area

If you’ve browsed the bulb onions we carry, you’ve probably noticed that there are long-day (LD) and short-day (SD) onions. This designation is critical as it refers to the hours of daylight necessary to trigger the onions to bulb up.

Long-day onions need 14 to 15 hours of daylight to bulb, while short-day onions need 10 to 12 hours of daylight. For the LD types that we carry, you can plant them from Virginia northward. SD types can be spring or fall-planted in Virginia and fall-planted in the South.

Step Two: Start Onions Early

Bulb onions are one of the earliest crops we start at Southern Exposure. We begin tucking seeds into cold frames between September and January. You can also sow them in a greenhouse or indoors any time from mid-September through mid-March.

Just remember, earlier is better! Earlier sowing means larger bulbs because plants will get larger before the heat and lengthening days signal them to bulb up. 

Onions should be sown about 1/4 inch deep in flats or trays. If you’re new to seed starting, check out this guest post, Starting Seedlings, by our friend Pam Dawling, author of Sustainable Market Farming.

Guest Blog Post: Starting Seedlings

Step Three: Select a Good Location & Improve Your Soil

Onions grow best in bulbs with full sun and light, well-drained soil with a pH between 6-7. Soil that is too acidic or alkaline will cause slow growth and late maturity.

Onions are heavy feeders that require fertile soil with plenty of organic matter. Onions need abundant potassium and phosphorous for good bulb formation and plenty of nitrogen during active leaf growth.

To improve your bed for transplanting, remove all weed growth, loosen the soil with a broad fork, garden fork, or tiller, and add a few inches of finished compost.

Step Four: Transplant Your Onions

Transplant your onions early. Onion seedlings are hardy to about 20 degrees F. Set them out in February or as soon as the soil can be worked in the spring.

Plant your onions 3 to 4 inches apart in rows 12 to 16 inches apart. Crowding can reduce production, particularly in poor soil. Refrain from pruning the tops, or your harvest will be significantly decreased.

Step Five: Mulch them Well

Mulch around your onions with a thick layer of straw, old leaves, grass clippings, or other organic material. Mulch will help suppress weeds and aid in maintaining moisture and nutrient levels.

Step Six: Keep Up with Weeding

Yes, this is every gardener’s least favorite chore and seems like a no-brainer, but it is critical with onions! Experiments have shown that weeds can cause a 4% reduction in onion production in one day or a 50% reduction in yield in 2 weeks.

Onions have shallow roots, so you may need to weed them by hand. Cultivation between rows should be shallow. 

Step Seven: Harvest & Cure Your Onions

Harvest your onions when most of the tops have fallen over.

Some folks like to break the tops of their onions by hand to accelerate harvest. However, we’ve found that this harms the storage ability of some varieties and helps the storage ability of other varieties.

It’s best to harvest onions after a few days without rain so the soil isn’t muddy and difficult to work with. Pull your onions, using a garden fork if necessary, and cure them for 2 to 3 weeks until the necks have thoroughly dried. 

Cure your onions somewhere with partial shade and good ventilation. After this period, you can clip the tops to within one inch of the bulb. 

Texas Early Grano OnionsStep Eight: Rotate Your Onions Next Season

As with all crops, onions are subject to specific pest and disease issues. To continue getting good production, it’s best to rotate your crops. We like to rotate onions on a three-year rotation and compost any onion residue to keep them pest and disease-free. 

If onions have given you trouble in the past, following this guide can help ensure good production. Start your onions early, provide plenty of space and nutrients, keep them weeded, and harvest them properly. Happy gardening!

Challenges of Growing Native Plants from Seed

Featured photo courtesy of Prairie Moon Nursery

Growing native plants can also be challenging in ways that we don’t often see in vegetables.  Since I haven’t seen much written up about what those challenges are, I’ve decided to write about them. I want vegetable growers to be better prepared when choosing native plants to add to your gardens, and when planting them.

I really don’t want to discourage you from planting natives, as there are lots of great reasons to grow them.  There’s a world of information out there about why it’s a good idea, including from various organizations mentioned below. For many native plant species, late fall and early winter are great times to put seeds in the ground. And despite all the factors mentioned below, in many cases, it can be really easy to grow native plants. After all, any plant native to your region has been know to grow without human help in your region.

Many customers have asked us about how many of the seeds we sell are native. The answer: a fairly small portion.  But some people might possibly be using the word native when what they really mean to ask about is, which plants are heirlooms. And we sell hundreds of heirloom varieties. Heirlooms are varieties that have been cultivated for long enough to get passed down through generations of humans, whereas natives are species that have been growing in a particular area, typically for thousands of years, without having been introduced by humans.

Why don’t we sell more natives? Well, part of the answer is that we’ve been working on it.  We sell a few more native plant seeds than we used to.  To read more about them, continue past the next section.

What often makes it hard to grow native plants

One of the most common challenges of growing native plants is that so many of them — including most Echinaceas — require a period of moist cold before they will have good germination rates.  This is called stratification. I find this intuitive regarding plants native to temperate climates because they need to be able to germinate in wild conditions where they experience a yearly period of moist cold.

Many native plants have other, more unusual, requirements before they will have good germination. For this reason, Prairie Moon Nursery (which carries seed packets of far more native plant species than any other company I know of) uses germination codes to indicate the kind of pre-planting treatment they recommend. For some plants, including Jewelweed (Impatiens capensis) and Early Horse Gentian (Triosetum aurantiancum) they even sell seed with a “?” germination code, indicating that they “are not sure of the best germination method for this native seed. Your input would be of interest to [them].”

Though it is difficult to start jewelweed seeds, this useful native plant self-sows more readily that we would prefer.

Most wild plants, including most plants native to any given area, have generally evolved to have seeds that will germinate over a much longer period of time than most cultivated plants. I find this intuitive as well, because in the wild, there are many unpredictable factors about what will happen shortly after a seed starts to germinate. For example, there might be a cold spell, a heat wave, a drought, or a change in which insects are in the area, eating which kinds of plants. If some of the seeds stay alive without sprouting for an additional month, or an additional year, or an additional ten years, that delay gives the species something of a back-up plan. In extraordinary cases, seeds have even been found to germinate after hundreds of years.

Unfortunately for seed companies, when a plant spreads its germination out over a long period, that usually makes it harder for humans to assess how many of the seeds in a given lot are alive, and harder to write good instructions about how to get them to grow, and harder to schedule times for planting and transplanting, among other challenges.

Occasionally we also see this prolonged period of germination in older heirloom varieties of crop plants that are closer to their wild relatives. For example, Choppee okra and Whippoorwill southern peas germinate over longer periods of time than most okra and southern peas.

Most native plants are perennials.  There are various advantages of perennials over annuals, including that you generally only have to plant them once. But when seed companies grow perennials, it takes us a lot more time to get to know them well enough to decide to sell them and to write descriptions. It also takes our seed growers a lot more time to grow them to a stage of maturity that provides a good harvest of seed.

Woodland plants, including those that are low-growing, are mostly perennial. Photo courtesy of Prairie Moon Nursery.

For most native plant species, there are no good instructions for how to harvest seeds or how to plant them. In many of these cases, it would be really challenging for us to write instructions for our own area and climate, let alone instructions that would work in most of the climates where our customers would plant those seeds. So, when we do add native plants to our listings, generally one of our main criteria is that they should, based on the information available to us, be relatively easy to grow.

In some cases, when we grow an unfamiliar plant, we make guesses about how best to take care of it based on how we take care of other plants in the same family. All plants are botanically grouped into families; there are hundreds in total. However, many native plants don’t have any widely cultivated relatives. Almost all widely-cultivated temperate-climate garden vegetables are in the same dozen families. All of these vegetable families also include native species, and some, such as the grasses, the legumes, and the asters, include a very wide range of wild, native species. 

One of the criteria we’ve used when deciding which native plant seeds to sell is ease of growing from seed.  Therefore, most, but not all, of the native plants listed below will grow well without any special treatment.  Ginseng and Goldenseal, as the most noteworthy exceptions, come with additional planting instructions.

What native plants Southern Exposure sells

As the folks at RVA Homegrown Natives describe well, the definition of “native” is somewhat fuzzy.  Every species is native to somewhere.  In any given location, a lot of plants could be considered native by some people and not native by other people.

Butterfly Weed, Scullcap, Dyer’s Coreopsis, Ginseng, and Goldenseal are also all native to broad areas of North America, including Virginia. Anise-Hyssop, Jewels of Opar, Red Drummond Phlox, and the Echinaceas that we sell are native to parts of North America, but not to Virginia.

Silverleaf sunflower (Helianthus argophyllus) is native to the Gulf coast and Southern Texas.

The Rudbeckias we sell, and most of the sunflowers we sell, are cultivars of species likely to be native to various parts of North America. Beach Sunflower (unavailable for 2023) and Silverleaf Sunflower are species types native to small ranges within the United States.

Wild Bergamot is native to broad areas of North America.  It’s also prone to spreading so vigorously that you’ll probably want to be cautious about where you plant it.  Lemon Bergamot is native to significant parts of the Southeastern US.

Lemon bergamot attracts has strongly flavored leaves and flowers that can be used in teas and foods.

Some of the squashes we sell — those in the species Cucurbita pepo — are cultivars of a species likely to be native to a range including parts of the Southeastern US.  In all our squash listings, we include the species at the beginning of the description, so you can tell which of the squashes we sell are Cucurbita pepo. However, based on the information I’ve found, I would estimate that cultivated squashes in the species Cucurbita pepo probably have their ancient ancestral roots primarily in Mexico rather than the United States — though I couldn’t find conclusive information on this.

Kars Egg squash, though it’s a Turkish variety, looks more similar than other squash to the pictures I find online of Cucurbita pepo var. texana, the U.S. ecotype of Cucurbita pepo.

Corn, beans, and squash have been grown in Eastern North America since long before Europeans first arrived on this continent. But, with the exception of wild Cucurbita pepo squashes, they were not growing in Eastern North America in pre-agricultural times. So they don’t fall into our category of native plants. These three crops, commonly referred to as the three sisters,  were first domesticated in other parts of the Americas, and they are native to those regions.

At Southern Exposure, we’ve been hoping to add Eastern Red Columbine to our listings.  It’s one of the best-known and showiest of the plants that are both native to our region and easy to grow from seed.  It did well in our trial gardens, impressing me with its bicolor flowers, and looking more attractive to my human eyes than many highly selected, hybrid kinds of columbine. We hope to offer it in future years.

Eastern Red Columbine (Aquilegia canadensis), a species native to most of the Eastern United States, including our part of Virginia

We’ve also been hoping to have Rudbeckia laciniata available for sale, but it seems that most of the plants on our land bear very few viable seeds. 

We’ve planted a range of additional plants native to the Eastern U.S. in our trial gardens, to help us decide which ones to sell. Among those that we’ve planted, and like enough to think about selling, are Boneset, Blue Vervain, Cherokee Sweet Mint, Cup Plant, Giant Yellow Hyssop, Joe Pye Weed, Maryland Senna, Partridge Pea, Purple Lovegrass, Virginia Mountain Mint, Yarrow, and Wapato.

Where to find more native plants

I’ve only found one company based in a Southeastern US state selling a wide range of native seed packets for gardeners: Roundstone Native Seeds. Roundstone also has a greater emphasis on regional ecotypes than any other company I know of.  When shopping further from home, consider that Prairie Moon Nursery has detailed maps of the native ranges of their seeds and plants.

There are also loads of nurseries selling mostly, or even exclusively, native plants. The Virginia Native Plant Society lists a few dozen such nurseries on its website. Meanwhile, as the folks at Maine’s Wild Seed Project point out, many big box stores are competing with local nurseries while selling plants that are not as suited to their particular region, with little or no attention to the ecological effects of their choices.

Besides the materials created by nurseries and seed companies, there is a world of other sources of information about identifying and growing plants native to our region. Here are a few I’d recommend:

6 Tips for Ordering Vegetable Garden Seeds

It’s that time of year again! After a short break, we’re already dreaming up next year’s garden, and soon, we’ll be flipping through the seed catalogs. Whether you’re an experienced grower or a first-time gardener, you should consider a few things when ordering vegetable garden seeds. 

Get your order in early.

In many areas, the demand for vegetable seeds has remained higher than usual since the pandemic. We’ve found that this is especially true for staple crops like heirloom dent corn and pole beans, which are more challenging for large seed growers to produce. Getting your order in early ensures you don’t miss out on your favorite varieties.

Additionally, getting your order in earlier will help ensure you get your plants started on time. It may seem unbelievable for new gardeners, but we begin the growing season in January, tucking cold, hardy crops like bulb onions and broccoli into flats indoors. Hence, they’re ready for transplanting in early spring.

USDA Hardiness Zone MapKnow your climate.

Knowing your hardiness zone can help you decide what plants and seeds best suit your area. The USDA just released an updated U.S. Hardiness Zone Map, and we have a Guide to Understanding Hardiness Zones you can check out.

One of the biggest things to consider when ordering your seeds for your climate is their days to maturity. Some crops like Vates Collards are quick, maturing in just 68 days, meaning you can get multiple successions even in many northern areas. Other crops like Rouge Vif d’Etampes (Cinderella) Pumpkin take a long, warm 120 days to mature.

Bulb onions, in particular, can be tricky. You’ll notice that there are long-day (LD) and short-day (SD) onions. Long-day onions need 14 to 15 hours of daylight to bulb, while short-day onions need 10 to 12 hours of daylight. For the LD types that we carry, you can plant them from Virginia northward. SD types can be spring or fall-planted in Virginia and fall-planted in the South.

Be realistic about your space and time.

It’s easy to end up with a vast seed order after flipping through the seed catalogs on a dreary winter day. Dreaming about all the heirloom varieties thriving in your garden invokes a sense of hope and excitement for the season to come. 

However, ordering more than you have the time and space for can lead to disappointment. It’s better to have a smaller garden you can manage and enjoy spending time in than a large, unproductive, weedy patch.

Cucumbers, beet, garlic in basketConsider pest and disease resistance.

Check out disease-resistant varieties, especially if you’ve had past issues with a specific crop. We carry many varieties with particular disease or pest resistance. You’ll find keys to disease and pest resistance on our website and catalog, like this tomato disease resistance key. For example, tomatoes marked “ab” are Alternaria (early blight) resistant, and cucumbers marked “cub” are resistant to cucumber beetles.

Think about pollinators.

A vegetable garden is nothing without pollinators—the healthier your local population of pollinators, the healthier and more productive your garden. Consider adding a few flowers to the mix. Even if you’re working with limited space, flowers can help improve production. One study found that flower strips and hedgerows in crop fields reduced pest pressure and improved pollination and yield. Flowers are worth it!

Gochugaru Hot Pepper
Gochugaru Hot Pepper

Focus on your favorites.

Your garden should bring joy to your life and kitchen. If you love Caprese salad, try out varieties like Lettuce Leaf Basil to maximize production or Red Rubin Basil to add a unique purple flair. Love kimchi or Korean sauces? Try growing the classic Korean Gochugaru hot pepper. Have you always wanted to make your hot sauce? Opt for something like the juicy Xochiteco Hot Pepper from Southern Mexico. 

On the flip side, if you never buy winter squash, adding them to your garden may not be the best plan because they’re an excellent storage crop. Use your space wisely and get the most enjoyment out of your vegetable patch possible.

When the catalogs start pouring in, making decisions can be tough! Keep these six simple tips in mind as you order your vegetable garden seeds this year.